DZone

The wide use of Geospatial Information Systems (GIS) has led to a number of features, including geofencing. In this case, geofencing is the tracking of an object in and out of a geofence. A geofence is a circle or polygon around a given area on a map. A circle can show areas that can track the entrance and exit from the marked area.

There are tools that can allow users to create and use geofences for software applications. One of these tools is PostGIS.

PostGIS

PostGIS is a geospatial extension of Postgres. You can find a description of PostGIS here. Also, some of the methods are mentioned here as well.  There are other methods that are good for geofencing as well. In fact, PostGIS can be used to create a geofence and to detect if a point is within a geofence.

Source: DZone